In order to exploit the induced female 2n
gametes for cassava (Manihot esculenta) breeding, a
detailed histological observation of female gametogenesis
was conducted to correlate with the morphological
characteristics of inflorescences and female
flower buds. The SC5 gynoecia at the stage of
prophase I were selected for unreduced megaspores
induction with 0.3 % colchicine and 1 % dimethyl
sulfoxide-soaked cotton plugs for 2 days. The resulted
female cyathia were artificially pollinated with ploidylevel
mixed pollens of SC10. Out of 250 hybrid
progenies, two plants which exhibited morphological
variations were confirmed as sexual tetraploids by
flow cytometry and chromosome counting. Our results
demonstrated that induction of 2n gametes combined
with hybridization can be an effective approach for
sexual tetraploid production for cassava.